It is known that for the winding of coils to be employed in the electric and/or electronic field, use is made of widely different types of automatic machines, which are adapted to satisfy even very different production requirements.
The present invention relates to a coil winder of the type so-called "in line". In these machines the coil support is essentially in the form of a rectilinear bar, on which are mounted as many rotating spindles as the number of coils to be simultaneously wound. The spindles, each of which carries a coil support, are controlled in their rotation speed and in the number of turns and/or turn fractions which they perform at each cycle.
In front of the rectilinear bar supporting the spindles, and parallel thereto, a second bar is arranged, with wireguides mounted thereon, one in correspondence of each of the spindles or coils. Said bar carrying the wireguides is moved to cause all the wireguides, in parallel, to perform movements so as to distribute the wires on the respective coils, or to twist the wire ends on the coil terminals, or even to lead the wires along other special paths.
According to known technique, said bar carrying the wireguides is centrally supported by a head controlling the movements, which is adapted to perform movements according to the three cartesian axes. Thereby, each wireguide mounted on the bar can be caused--for instance under numerical control--to perform movements in any desired direction.
The main drawback of these machines lies in the system for supporting the wireguides carrying bar. In fact, taking into account that said bar is normally of considerable length--for instance, of the order of 100-120 cm, which is indispensable for carrying about twenty wireguides in parallel--the support thereof, in a central position, is not adapted to guarantee a reliable control of the bar itself.
In other words, the cantilevered support of each half of the bar in respect of the centrally positioned control head the inevitable slck between guides and slides performing movements according to the three axes, as well as the actual flexibility of the bar itself, are all factors which--under the stresses and vibrations produced by the wire sliding in the wireguides--are considerably harmful for the perfect control of the wireguides, especially those positioned closer to the ends of said bar. For these reasons, it is also practically impossible to use bars of a length exceeding that specified heretofore, the control of which would cause great problems.
This is why the above coil winders in line have been, up to date, mainly designed to satisfy requirements of high production speeds, not caring about a high precision in the control of the wireguides and, thus, in the production of the coils.
As a matter of fact, it has also been provided to manufacture coil winders in line, having enough precision in the guiding of the bar, for instance by producing the control head with slackless guides, or with the possibility to adjust the slack; nevertheless, such machines are first of all extremely costly and difficult to set up and, furthermore, through wear, they are apt after a short while to suffer the same drawbacks which have been pointed out hereabove.